Signaling system



July gs, 192s. 1,547,873

R. M.. HOPKINS v SIGNALING SYSTEM 'Filed March 15,, 1918 71IEiEIIIHI M nREE/in IN VE IV TOR lT/VESS A TTORNE Y Patented Judy 2%, i925.

- rennan M. HOJPKINS, or no'rnnnronn, new JERSEY, assrenon T0 AMERICANDIS- rnrcr TELEGRAPH comramz, or JERSEY CITY, NEW

new JERSEY.

dtiigm rai- J'ERSEY, A CORPORATIQN OF SIGNALING SYSTEE.

Application filed March 13, 1918. Serial No; 222,077.

To aZZ whom it may concem:

Be it known that I, RICHARD M. Hormns, a citizen of the United States ofAmerica, and a resident of Rutherford, in the county of Bergen and Stateof New Jersey, have invented a certain-new'and useful Signaling System,of'which the following is a specification.

This invention relates generally to alarm systems or detectionsystems,more especially to systems for the protection of vaults and the likefrom burglary, and is designed to give a positive and reliable automaticelec trical indication at a central oiiice when any attempt is made tobreak into or enter'vaults protected by it. By this system the ordinaryexpensive wire or foil linings covering the walls, ceilings, and floorsof vaults is sible forthe alarm. Furthermore, the sys-- tern is suchthat conversations within the vault orpremises protected may be heard,at the central station. The system herein described embodiesimprovements over the system for the same purpose set forth in thepatent to myself and to J. F. D. Hoge, No. 1,192,312, dated July 25,1916, and depends for its action upon the fact that if an entrance to avault or other protected premises is forced, or an attempt made toenter, a noise of some kind will necessarily be made. This noise willcause the diaphragms of certain sensitive detectors placed in the vaultto vibrate, and, in vibrating, to vary their respective resistances. Inthe system of the said' prior patent, such detectors, when theyoperated, produced telephonic fluctuations in their circuits, which wererectified by rectifiers'located in or about the protected. premises, therectified currents operating a relay by which signals were transmittedto the central station; but according to the present invention, thesetele sensitiverelay, whereby other apparatus is operated. Bytransmitting the telephonic currents produced by the'detectors to the atthe central station where they are readily supervised and maintained ineflicient oper-. ative condition, but also it is possible for thecentral station operator to listen in whenever desirable, and therebythe central station operator may determine'the, character of the noises;also the-central station operator-may 'at any time ."listen in and hearconversations in the vault, if any.

. Furthermore, by the transmission of telephonic currents, rather thanrelayed .cur-' rents. to the central station, the system is renderedpractically immune from the effects of sneak currents, induction fromexternal sources,-etc., and testing, by the central station operator ofthe apparatus at the subscribers station is rendered much moreeffective.

My invention' cbnsists in the novel arrangement of circuits, apparatus,and instruments, as hereinafter'described and particularly pointed outin the appended claims.

The objects of my invention are to improve burglar or detection systemssuch as.

described; to. make such systems more reliable, and more easily tested,andto .in-

crease the degreeof supervision which may be GXGI'CISGd at thecentralstation both over the instruments of the system and over what goes on inthe protected premises; and to avoid disturbance from induction, sneak"currents, and other external disturbances. .I will now proceed todescribe my inventlon wlth reference to the accompanying drawing,showing, more or less diagrammatically, one particular embodiment of theinvention; it being understood, of course, that the circuits andinstruments are susceptible of considerable modification with outdeparture from my invention.

' In the drawing: A A designate telephone transmittcrs, preferably of avery sensitive type; of which transmitters there may be as many asdesired within the protected premises. In connection with each of thesetransmitters I usually provide a tapper A of the general nature of atelegraph relay or sounder, which relay or sounder is employed as asound producing device,

which may be set in operation from the central station and by itsoperation will pro duce sounds which will be heard through thetransmitter A. and the circuit thereof. Theserelays are commonly locatedwithin the enclosures of the corresponding transmitters, and by thevibration produced by their operation tend to keep these transmittors insensitive condition.

Current is supplied for the operation of these transmitters A. by abattery 15 located at the central station, and customarily di- Videdinto two unequal portions, for reasons hereinafter described; theconnection from the central station battery to the transmitters A beingthrough trunk lines 1 and 2, which are customarily protected againstinduction either by being formed into a twisted telephone pair whenlocated in cables, or by suitable transposition when overhead lines areemployed; all as is well known in telephone practice. Customarily, .theincoming trunk line 1, passes through the contacts of a door protector 3v (such door protector being one of the well known contact deviceswhereby the local instruments are cut out when the door of the vault isopened, and are placed in circuit again when the vault door is closed)thence the circuit passes through a combined ammeter and relays,located, usually, external to the vault, but in. a position convenientso that the subscriber, upon closing the vault. door, may note signals,if any, transmitted from the central station. This ammeter 4: alsoserves as a means for continuously supervising the subscribers equipmentfrom,

the central station; the test being obtained by increasing the currentin the line sufii ciently to cause this ammeter-relay to close circuitfrom a subscribers battery 5 through "the tappers 1%.", so causing thetappers to operate and thereby produce sounds which, in turn, will causethe transmitters A to transmit telephonic currents to the centralstation, and there operate the central station indicating apparatus.

Usually, there is an u.nprotected.period during the day, when the vault"door is open, and therefore, when supervision l'rom the-central stationnot desired, during such period the apparatus in the vault is out out,and also short-circuited through line 8, by the door protector 3; duringwhich period the armature of the ammeter 4- is against its back stop.But as soon as the vault door is closed, the short-circuit is removed,the transmitters A are connected to line, the armature of the ammeter 4moves to its mid-position, and upon increase of current strength in theline, fortest purposes, such armature will move against this front stop,so operating the tappers A" as described.

At the central station, trunk line 2 is com nected to the switch arm ofthe switch C, by which that trunk line is connected normally toconductor 7 leading to the dividing point between the two sections ofbattery B; but by throwing the switch arm to its opposite position. thistrunk conductor 2 may be con nected through the telephone receiver 8 toboth sections of the battery'B in series and thence through conductor 9,actuating coil 10 of a delicate ammeter-relayll, and primaries 12 and 13of transformers l l and 15 to a telephone jack l6, and thence, throughconductor 1, back through the actuating coil of ammeter-relay 4, and thetransmitters A to trunk line 2.

lit J will he noted that with the-arm of the switch C in the normalposition shown, only the shorter section of battery 3 is in the linecircuit. For test purposes, by reversing the position of the-switch arm,both sections of the battery are connected in circuit in series.v IAmmeter-relay 11 serves as means for constantly indicating the strengthof the line current and maintaining that line circuit under test.

' The transformers 14 and 15 have secondaries, 21 and 22' respectively,which second:

aries are connected in series with each other, with an intermediate tapwire 23 leading through the actuating coil 24 of adelicate relay 25 tothe two plates of the rectiiiers 26; the outer terminal of the secondary21 being connected through a conductor 27 to the filament of one 'oi'these rectifiers, the outer terminal of secondary 22 being connectedsimilarly by conductor 28 to the filament of the other rectifier. Theserectifiers are provided with the usual hatteries 29 in their filamentcircuits, controlled lay a double arm switch D. it will be understood bythose skilled in the art that these rectifiers together rectify thetelephonic currents transmitted through the circuit 1--2 through theoperation of transmitters at the subscribers station, and communicatedinductively through the transformers 14: and 15 tothe rectifier circuits27-9253 and 28'.23 and to the actuating coil of relay 25. This relay,when. ac tuated, closes circuit 9-17 through the coils of drop relay 18,so actuating indicating devices 19 and 20.

Drop relay 18 is an instrument comprising two magnets, E and F, togetherwith shutter armatures E. and F respectively, of which E will drop andclose contact when the magnetization of magnet E demergers usually abell and a lamp. respectively) through a switch D.

30 designates a telephone-receiver at the subscribers station, throughwhich receiver 7 the subscriber may listen to signals trans eated andwhen the armature F is drawn upward against its contact by an abnormalcurrent through the magnet F, the indicating devices 19 and 20 arethereby actuated. During the-non-protection period, the switch D isswung over to the other contact, thus disconnecting the armature F andconnecting the armature E audits contact operatively, to the indicatingcir cuit. Normally the armature E is attracted by the magnet E and heldaway from itscontact, but if the circuit 121is broken or its resistanceis greatly increased, the armature E will drop. and close the circuitthrough the indicating devices 19 and 20. v

The operation of the'system is as follows: Normally, the switch arms ofswitches C, D, and D are in the positions shown, the short end only ofbattery B is to line, and the transmitters or detectors A are incircuit. Y i

During the protected period the needle of the ammeter-relay 11 isagainst its righthand contactfithus energizing the magnets E and F ofthe relay 18, through the conductors .9, 9 and 17. By reasonoftheresistance 31, the current flowing through thecircuit is not strongenough to cause the magnet F to lift its armature F and consequently thelocal circuit through the in dicating devices 19 and 20 remains open.'

Now, should sounds be produced within the vicinity of the detectors A,such detectors, by their operation, will transmit telephonic currentsthrough circuit 12, and

these telephonic currents, acting'inductively through transformers M and15, will produce currents in the circuits of rectifiers 26, whichcurrents will be rectified by such rectifiers and will cause thaneedleof relay 25 to close circuit '917, thusv shunting the resistance 31 andcausing the current through magnet F to increase sufficiently to attractits arm'atureF and so causing indicating devices 19 and 20 to operate.

It the line 1-2 should become broken thuscutting oil the current throughcoil 10, the needle of relay 11 will swing over to its left handcontact, thus shunting the resistance 31 and causing the current throughmagnet 1* to increase. thereby attracting its armature F and closing theindicating circuit through indicating devices 19 and 20.

During the non-protective period the needle ofthe relay 11 is normallyagainst its right hand contact so that the circuit is closed through themagnets E and F of the relay 18 and the armature-E is attracted and heldaway from its contact. During this non-protective period the switch D isswung over to dotted line position, thereby bringing the armature E andits contact; into operative relation with the local circuit containingthe indicating devices 19 and 20. It now, the circuit 12 becomes brokenorits resistance is abnormally in- I creased,-the armature E will dropfrom the magnet E and close the circuit which actuates the indicatingdevices 19 and 20.

Periodically, during the protected period, the central station operatorshould operate switch C, so throwing the full battery B into circuit andoperating the sound producing devices A, thereby causing the detectors Ato operate and deflect the needle of the 'ammeter relay 25, whichdeflection can be observed by the central station operator; also at suchtime the central station operator can hear the operation of these soundproducing devices A through the telephone receiver 8.

,By connecting a portable telephone receiver (not shown) to the circuit12, at the .jack' 16, the, central station operator can at any time,during the protected period, hear what is going on in the protectedpremises. This jack 16 inay be understood to be a diagrammaticrepresentation of telephonic apparatus for this purpose.

When, at the conclusion of the non-protection period, the vault door isclosed, the

subscriber listening through his telephone receiver 30, may hear signalstransmitted by the central station operator ing the switch C), therebyassuring the subscriber thatthe system is in full operation and that hispremises are under protection. l It will he noted that since telephoniccurrents are transmitted by the detectors A to the central station, suchtransmission will not he interfered with by tampering withtelephonicdines 1--2 (except as" such tampering may open the circuit),and, there fore, such tampering does not interfere with the transmissionof signals by thosedetectors; and for the same reason, sneak currents,inductive disturbances, and thedike' will not interfere with thetransmission of such signals by transmitters A. Furthermore, breaking orshorting of line conductors 1, 2, will cause a potential discharge inthe primaries of induction coils 14 and 15, with consequent developmentof inductive hick in the corresponding secondaries, so causing themomentary operation of relay fiog'so the line circuit is not only underthe supervision of balanced relay 18, but is (by reversunder the farmore sensitive supervision of relay 25. Other advantages of the improvedarrangement are as follows:

The batteries for supplying current to the transmitters A are located inthe central station where they can be supervised and changed at anytime.

' The rectifiers, switch controlling apparatus, relays, etc. of adelicate nature, are located in the central station under supervisioninstead of in the subscribers premises.

It is possible with the present system to connect a telephone receiverinto the alarm circuit at the central station and hear conversations ornoises in the vicinity of the vault.

\Vith the present system the current is supplied to the transmittersfrom the central station, the current being supervised.

With the present system there is a visible indication that therectifiers are in operative condition;

The present system is provided with an indicating meter installed in thesubsc-ribers premises which registers the amount of current flowingthrough the microphones and is an indication to the subscriber of thecondition of his protection.

What I claim is:

1. An alarm system, comprising a central station, a subscribers station,a sensitive sound detector at the subscribers station; a sensitiverelay, an electric generator, and a transformer, at the central station;a-single circuit connecting said stations and including said detector,said relay, said generator and the primary ofsaid transformer; a currentrectifier at the central station connected to the secondary of saidtransformer and an clectro-responsive'device in circuit with saidrectifier and controlled by the rectified current. v

2. In an alarm system as set forth in claim 1, a sensitive relay at thesubscribers station operatively connected to'said circuit, and means atthe central station for causing an increased current from saidgenerator.

over said circuit, whereby the relay at the subscribers station can beactuated from the central station for the purpose of transmitting asignal.

emmas crease or decrease in line current strength, ,a relay at thesubscribers station arranged to be operated by material variation incurrent strength in said circuit, and sound producing means operativelyassociated with one of the detectors and controlled by said subscribersrelay and arranged to be set in operation thereby to cause operation ofthe corresponding. detector.

4. An alarm system comprising in combination a central station, asubscribers station, a circuit connecting said stations, and including asource of current supply, one or more sensitive sound detectorsconnected to said circuit at aid subscribers station, a sensitive relayat the central station and means at the central station for operatingsaid relay by telephonic currents transmitted from said detectors, asensitive relay at the subscribers station and included in said circuit,a local circuit controlled by said subscribers relay, the latterarranged to close said local circuit upon material change producingmeans in said local circuit and in proximity to one of said detectors,.and arranged to be operated by closure of the local circuit, and meansat the central station for varying the strength of the line RICHARD M.HOPKINS. lVitnesses GEO. Boson,

HARRY J. MoCANn.

- in line current strength from normal, sound

